(83 camaro) the tail lights don't work when the light switch is on but brake lights do work...so I checked out the bulbs to find one blown (and the tail fuse was blown as well)...I replaced the bulb but the tail lights still don't work but brake lights still do!!! HELP ...but the fuse no longer blows!

you'll have to search a bit, i dont have the links saved and im running out the door. Brake lights get power from a seperate wire (blue) Your left signal gets power from yellow, right signal gets power from green. All others including your regular tail light (its double filament) gets power from brown wire.

You should start probing the wires at the diff connections where the harness separates front to back (mine had one of these in the back and one in the rear speaker area at the floor. Start at the back since thats the easiest to get to. Check for voltage. You could have bad wiring, bad ground, bad bulb socket, bad head light switch

Turned out my issue was the connection went bad between the harness disconnect near rear speaker and rear hatch area disconnect where GM decided to use solidcore wire and multistrand copper. I had to run a new power wire from where the multistrand showed voltage and now its alllll good.

here's a good start:
http://www.austinthirdgen.org/mkport...ody_wiring.gif

the tails and stop lights are on different circuits, so that would explain why one set can still work when the others don't. probing for connectivity will be your best shot at getting things working again.